Kamala Harris has arrived in Chicago for the Democratic National Convention (DNC), where she will be officially confirmed as the party’s presidential candidate.
After a day of campaigning in the swing state of Pennsylvania with running mate Tim Walz, she flew to O’Hare Airport on Air Force Two.
Her Republican rival Donald Trump held a rally in Pennsylvania on Saturday.
Ms Harris is expected to join President Biden on stage when he addresses the convention on Monday.
Pennsylvania has been a key battleground in recent presidential campaigns, with Donald Trump winning the state in 2016 and Joe Biden in 2020.
A new CBS News poll shows Trump and Harris are neck-and-neck in swing states such as Pennsylvania, Michigan and Wisconsin.
In a speech on Sunday, Ms Harris indirectly criticized her opponent, suggesting he was a “coward” whose politics focused on crushing rivals.
“What we know is that the true measure of a leader’s strength is based on the people you lift,” she told a crowd of supporters.
“Anyone who tries to beat someone else is a coward.”
A day earlier, in the same state, Trump called his Democratic rival a “crazy guy” and boasted that he was “much better looking” than her.
Ms. Harris arrived in Chicago on Sunday ahead of the Democratic National Convention, where delegates will recognize her as the nominee for the Nov. 5 election.
The convention will culminate on Thursday with Ms Harris giving a prime-time speech after formally accepting the party’s nomination.
Security was tight around the venue ahead of the four-day event, where tens of thousands of pro-Palestinian protesters are expected to rally in Chicago.
